The objectives of the proposed research are to determine the annual cycle of vibrios and related organisms in the water, sediment and aquatic flora and fauna of a tank and canal of a cholera endemic area, to identify those species of Vibrio, including Vibrio cholerae and Vibrio parahaemolyticus, found in these areas, to examine freshly isolated Vibrio stains for presence of extrachromosomal elements, and to develop a genetic system for these organisms. The ecological studies will include examination of water, sediment, flora, and fauna samples collected at appropriate intervals of time for determining the seasonal abundance and distribution of Vibrio spp. Incidence of antibiotic resistance among vibrios in situ will also be examined. Correlations between presence of plasmids and presence of antibiotic resistance, enterotoxin production, and other characteristics derived from the systematic analyses will be sought. The data obtained in this study will be maintained on computer and will be analysed, using the data files of the Principal Investigator gathered and stored on computer during earlier studies of the genus Vibrio. An on-line identification system for the Vibrio species will be established.